Your search for "effervescent tablet" revealed the following:

On Sale from £32.16 Regular price £40.00 Sale
Sale price £52.99 Regular price £70.00 Sale
On Sale from £35.71 Regular price £50.00 Sale — Sold Out
Sale price £79.95 Regular price £90.00 Sale
On Sale from £66.60 Regular price £90.00 Sale
Sale price £43.96 Regular price £70.00 Sale — Sold Out
Sale price £246.90 Regular price £300.00 Sale
Sale price £94.99 Regular price £130.00 Sale
Sale price £306.11 Regular price £400.00 Sale
On Sale from £52.25 Regular price £70.00 Sale